S1 Upgrade-Kit

The S1 Upgrade Kit includes three firmware options that change the preload force of your Infinity Flow S1. These firmware versions are designed only for upgraded S1 units and must be uploaded manually (they are not accessible through the app).

• Low Preload Force – About 20% lower than stock. Best for lighter setups where less pressure is needed.
• Medium Preload Force – Matches the original stock S1 preload.
• High Preload Force – About 30% higher than stock. Provides added preload for challenging filament paths or long Bowden tube runs.
  

Since wear over time can reduce the force of a standard S1, the medium setting on an upgraded unit may actually feel stronger than a well-used S1.

This reduction in preload force over time has been solved in the S1+ (and S1 upgrade kit).

To switch between these levels, simply upload the corresponding firmware file to your upgraded S1.

No—the Upgrade Kit does not convert an S1 into an S1 Plus. While it uses the same gearboxes, motors, and filament junction as the S1 Plus, it does not replace the main PCB.

Because of this, several S1 Plus features remain exclusive to that model:

• Wi-Fi connectivity
• S1 Plus App integration
• Adjustable preload force via the app
• Built-in electrical safety protections (motor backdrive protection, variable motor current for cooler operation, overvoltage protection)

The Upgrade Kit focuses solely on mechanical reliability—with ASA-printed components that resist creep, stronger gearboxes, and an updated filament junction to reduce wear and filament grinding. These upgrades extend the life of your S1, but they do not add the full feature set of the S1 Plus.

If you want improved reliability while keeping your current setup, the Upgrade Kit is a great choice. If you want all the advanced features, upgrading to the full S1 Plus is the way to go.

The S1 Upgrade Kit is focused on mechanical reliability, not electronics. The S1 Plus main PCB is not included for several important reasons:

1. Individual Calibration – Every S1 Plus is individually calibrated and tested in-house before it ships. This ensures that preload settings, safety features, and firmware are all tuned correctly for each unit. That level of calibration cannot be replicated with a user-installed upgrade kit.
2. Firmware Security – The S1 Plus boards are connected to our cloud servers and cannot be directly reflashed by users. This is for security reasons, so that only verified firmware updates can be pushed to connected devices. A “default” calibration cannot be used, because we need the ability to send custom firmware adjustments when necessary for upgraded S1's thave have not been pre-calibrated.
3. Flexibility of the Original S1 Boards – By keeping the original S1 electronics, users can still take advantage of firmware updates we release for different preload settings. These can be flashed directly by the user, giving more flexibility in setups that may require lighter or heavier preload force.

Because of these reasons, the Upgrade Kit does not include the S1 Plus main PCB. Instead, it focuses on improving the mechanical components of the original S1—gearboxes, motors, and the filament junction—for a significant reliability boost without changing the device’s electronics.

No. While the Upgrade Kit replaces the gearboxes and filament junction with parts printed in ASA for greater heat resistance and long-term durability, the electronics inside the S1 are still vulnerable to heat. Prolonged exposure inside a heated filament dryer can damage the PCB and other electronic components.

For the best results, we recommend keeping the S1 outside of heated environments. If you need to use a dryer, route a filament tube from the dryer’s outlet to the S1’s inlet. This setup keeps your filament dry while protecting your S1 from heat damage.

The S1 Upgrade Kit brings significant reliability upgrades to the original S1 by replacing its most critical moving parts—the gearboxes and the filament junction.

• Gearboxes – The new design offers improved wear resistance, reducing the chance of filament grinding during reloads.
• Filament Junction – Redesigned to be stronger and more consistent. This reduces misfeeds and improves reliability during automatic reloads.
• ASA Printed Components – Both the gearboxes and filament junction are now printed in ASA, rather than PLA+. ASA resists heat better and is far less prone to plastic creep over time, which means critical parts maintain their shape and performance better over time in harsher environments.

Together, these upgrades make the S1 less likely to grind filament, jam, or wear down under the constant preload force. The result is smoother operation, fewer reload issues, and a much longer service life for your S1.